1. Field of the Invention
The present invention relates to a method of, and an apparatus for, cleaning photo film, especially for photo film having a magnetic recording layer on a reverse surface to an emulsion surface. More particularly, the present invention relates to a method of, and an apparatus for, cleaning photo film during the manufacture.
2. Background Arts
A new type photo film cartridge has been developed and disclosed, for example in U.S. Pat. Nos. 4,834,306 and 4,832,275, and JPA 3-37645 (U.S. Pat. No. 5,271,577), wherein an entire length of photo filmstrip is wound into a cartridge shell before and after use, and a film leader is advanced out of the cartridge shell in response to an unwinding rotation of a spool of the cartridge shell. This new type photo film cartridge is easy to load in the camera, easy to handle and thus improves work efficiency during the photographic processing.
It is also known in the art to provide a transparent magnetic recording layer on the new type photo filmstrip so that photographic data or print data may be magnetically recorded on the photo filmstrip in association with respective frames. When manufacturing the photo filmstrip, an emulsion layer is applied on an obverse surface of a wider web of base film, and the magnetic layer is applied on a reverse surface of the wider web. Thereafter, the wider web is slit into narrower webs of a constant width. The narrower web is perforated and cut into individual filmstrips of predetermined lengths, each of which is then wound into the cartridge shell.
As a result of the slitting, particles of film or swarf are produced from the cut edges of the narrower webs. The film swarf and dust floating in the factory can be put on the photo filmstrip. If the swarf and dust are put on the magnetic recording layer, the swarf and dust accumulate on a magnetic head, thereby deteriorating sensitivity of the head and the signal frequency characteristics. This may result in writing errors or reading errors. The swarf or dust on the emulsion surface results in black spots in the images exposed on the photo filmstrip. The swarf or dust on either surface can result in black spots in the photo-prints since the printing light transmits through the photo filmstrip.